The characteristics of a novel, double toroidal, electrostatic electro
n energy analyser, with input and output optics, have been established
. The energy and angular dispersed image on the surface of a microchan
nel plate detector enables parallel data processing and significant ga
ins in efficiency. The characteristics of the toroids and lenses, incl
uding time dispersion, have been modelled using standard relaxation te
chniques and are compared with measured values. The calculations predi
ct hemispherical radial magnification and second order focusing with 0
.7% accuracy. The differences between point and distributed object siz
es, such as may occur with solid and gas targets, are indicated. Measu
red elastic differential cross sections for 50 eV electrons scattered
from argon and an Auger spectrum from argon are in good agreement with
modelled data.